Fetal ultrasound exams on more than 87,000 mice that were exposed to chemicals that can induce random gene mutations enabled developmental biologists at the University of Pittsburgh School of Medicine to ...

A University of Colorado Cancer Center study published today in the journal Nature Genetics describes a newly-discovered, heritable genetic cause of acute lymphoblastic leukemia (ALL), namely mutation of the ...

Congenital diaphragmatic hernia (CDH) is not as well known as muscular dystrophy and cystic fibrosis, but like them it is a life-threatening birth defect, and is just as common. Occurring in one in 3,000 ...

Researchers at the University of Virginia School of Medicine have developed a compound that delays leukemia in mice and effectively kills leukemia cells in human tissue samples, raising hopes that the drug ...

Epilepsy is a brain disorder that afflicts more than 50 million people worldwide. Many epilepsy patients can control their symptoms through medication, but about 30% suffer from intractable epilepsy and are ...

Among cancers, scientists have spent their entire research careers looking for cellular similarities that may lead to a single cure for many cancers –– the rare chance to have a single answer to a multifaceted ...

By genomic sequencing of leukemia cells from relapsed patients at different stages, scientists have discovered key details of how acute lymphoblastic leukemia (ALL) cells mutate to survive chemotherapy. These ...

Messenger RNAs (mRNA) are linear molecules that contain instructions for producing the proteins that keep living cells functioning. A new study by UCL researchers has shown how the three-dimensional structures of mRNAs determine ...

Researchers at the San Diego Supercomputer Center (SDSC) and the Moores Cancer Center at the University of California, San Diego, have described for the first time the molecular mechanism of cancer development ...

For infants with severe combined immunodeficiency (SCID), something as simple as a common cold or ear infection can be fatal. Born with an incomplete immune system, kids who have SCID—also known as "bubble ...

In a group of patients diagnosed with colorectal cancer at 40 or younger, 1.3 percent of the patients carried germline TP53 gene mutations, although none of the patients met the clinical criteria for an inherited ...

Since December, an outbreak of swine flu in India has killed more than 1,200 people, and a new MIT study suggests that the strain has acquired mutations that make it more dangerous than previously circulating ...

World Kidney Day, celebrated on 12 March 2015, is commemorated to raise awareness of the importance of our kidneys to our overall health and to reduce the frequency and impact of kidney disease and its associated health problems ...

A team of researchers has sequenced the genome of classical Hodgkin lymphoma, illuminating exactly which proteins are altered in individual patients. The findings could pave the way to delivering personalized ...

Mutation

In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism itself, by cellular processes such as hypermutation. In multicellular organisms with dedicated reproductive cells, mutations can be subdivided into germ line mutations, which can be passed on to descendants through the reproductive cells, and somatic mutations, which involve cells outside the dedicated reproductive group and which are not usually transmitted to descendants. If the organism can reproduce asexually through mechanisms such as cuttings or budding the distinction can become blurred. For example, plants can sometimes transmit somatic mutations to their descendants asexually or sexually where flower buds develop in somatically mutated parts of plants. A new mutation that was not inherited from either parent is called a de novo mutation. The source of the mutation is unrelated to the consequence, although the consequences are related to which cells were mutated.

Mutations create variation within the gene pool. Less favorable (or deleterious) mutations can be reduced in frequency in the gene pool by natural selection, while more favorable (beneficial or advantageous) mutations may accumulate and result in adaptive evolutionary changes. For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.

Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness. Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.

Mutation is generally accepted by the scientific community as the mechanism upon which natural selection acts, providing the advantageous new traits that survive and multiply in offspring or disadvantageous traits that die out with weaker organisms.